1. Field of the Invention
The present invention relates to the preparation of a finely divided powder of an alkaline earth metal titanate, the titanate thus prepared and the formulation thereof into ceramic compositions used for the manufacture of condensers or resistors therefrom.
2. Description of the Prior Art
The alkaline earth metal titanates, and especially barium titanate, are compounds which are widely used in the preparation of ceramic compositions.
Various methods for the preparation of barium titanate are known. It is prepafed, in particular, by forming a chamotte between a barium salt containing a volatile anion, for example, barium carbonate, and titanium oxide (Chemical Abstracts, 20, 166, 870 g). In this case, the reaction takes place at temperatures ranging from 1000.degree. and 1400.degree. C., which gives rise to temperatures upon completion of sintering, during the preparation of the dielectric formulae, higher than 1350.degree. C.
Such a process has many disadvantages.
First, the need to carry out the reaction and sintering at high temperatures entails a considerable consumption of energy.
Furthermore, it is known that in the manufacture of a dielectric composition, in addition to the barium titanate, materials are used which serve to ensure contact between the different layers of titanate forming the dielectric. However, taking account of the fact that the sintering reaction takes place at high temperature, it is necessary to use materials able to withstand these conditions, and therefore having high melting points. In the case of the condensers, for example, this mandates a selection of precious metals such as, for example, silver, platinum and palladium.